One fun fact about sand dollars is that these animals are closely related to sea urchins. In addition, the white or off-white sand dollar skeletons found on beaches are called "tests," and their five-jawed mouths are at the center of the star-shaped markings on the tests.Continue Reading
Sand dollars are echinoderms, like sea urchins, sea cucumbers and starfish. Live sand dollars are covered in short spines that come in a variety of colors, including purple, green, black and reddish brown. They use these spines to burrow into the sand, move along the sand and collect food particles. When the particles come to rest on the spines, the animal uses its pincers, cilia and five tube feet to transport the food to its mouth.
The mouth, called Aristotle's lantern, consists of five jaw sections used to grind up plant and animal matter. A sand dollar may spend as long as 15 minutes grinding its food before swallowing it, and it can take as long as two days to digest its food.
The shell-like tests found washed up on beaches are sand dollar endoskeletons. The tests consist of rigid, fused plates and differentiate sand dollars from other echinoderms, which have skeletons made up of smaller, more flexible skeletal plates or small bony structures called ossicles.Learn more about Landforms
Uluru began to form over 550 million years ago when sand, eroding from the Peterman Ranges, built up into thick deposits. Some 50 million years later, these deposits were compressed into sandstone by the weight of a sea that eventually disappeared. Within another 100 million years, geological events caused the sandstone to tilt almost 90 degrees, resulting in Uluru.Full Answer >
The composition of sand is dependent on the geographical area where the sand is located. Most sands are composed of small land sediment particles, minerals, rocks and organic matter that has been eroded and ground down over many years. For this reason, sand composition varies greatly.Full Answer >
Different types of sand include olivine sand, volcanic sand, coral sand, garnet sand and Foraminifera sand. Other types of sand include sand from the moon, sand from Mars, frac sand, gypsum sand and ooid sand.Full Answer >
Many animals make their home in the desert, including bighorn sheep, scorpions, ostriches, kangaroo rats, echidna and camels. Certain animals are only present in specific deserts.Full Answer >